公开(公告)号：US4836681A

公开(公告)日：1989-06-06

申请号：US867026

申请日：1986-05-27

Applicant: John G. Van Saders ,  Andrew Tarasevich ,  Michael C. Reichenbach

Inventor： John G. Van Saders ,  Andrew Tarasevich ,  Michael C. Reichenbach

IPC: G01J9/02

CPC classification number: G01J9/02 ,  G01J2009/0234

Abstract: Electro-optical apparatus measures the average relative phase of an incident wave fringe pattern. The subject fringe, e.g., an interferometric pattern, passes through three sections of an optical mask, one characterized by fixed transmissivity and the other two by quadrature-displaced spatial fringe patterns. The light passing through each section is separately collected and detected to average the respective incident wave/mask section interactions. The phase of the incident fringe pattern relative to the mask is then determined by arithmetically processing the detected signals.In accordance with one aspect of the present invention, the subject fringe pattern is time modulated and the quadrature-shifted mask signals A-C coupled to obviate the requirement for the third, fixed transmissivity mask section.

Abstract translation: 电光装置测量入射波纹图案的平均相对相位。 被摄体边缘（例如干涉图案）通过光学掩模的三个部分，其中一个特征在于固定的透射率，另外两个部分通过正交位移的空间条纹图案。 通过每个部分的光被单独收集和检测以平均相应的入射波/掩模部分相互作用。 然后通过对检测到的信号进行算术处理来确定入射条纹图案相对于掩模的相位。 根据本发明的一个方面，本发明的条纹图案是时间调制的，并且正交移位的掩模信号A-C耦合以消除对第三固定透射率掩模部分的要求。